Weird -- flapper misses hole

We've started having a weird problem with the toilet in our powder room. It's a Briggs that was here when we bought the house, and I think it's probably original (ca. 1988). Not sure if the innards are original.

The problem that's recently developed is that the flapper will come down slightly off-center from the hole, catch on the edge, and not seal. So the toilet will continue running forever (or until someone jiggles the handle and makes the flapper seat properly). The chain isn't getting tangled or anything, the flapper just isn't always landing right.

Do I just need to replace the flapper (I'm guessing I might as well just replace everything in the tank if I'm going to do that), or is there some easy fix I can do?

(Yes, I should probably replace the whole toilet, but we're in the midst of a major master bath remodel right now, and I'd rather keep the powder room toilet working a bit longer).

Thanks.

Replace the flapper!

Dumb question. Are flappers pretty much universal, or do I need to be careful to get one that's compatible with my toilet and existing hardware?

1988 Briggs?
That's pretty universal.
Just make sure the flapper moves on the pins.

Some flappers come with a ring that slides over the overflow tube, and they also often have loops that will fit over tabs on the overflow. If you have tabs, DO NOT use the ring...cut it out and only use the tabs.

Thanks all. I picked up a new flapper at Dunn Lumber today and that seems to have fixed it.